Polycarpa mytiligera, known as the Sheep's foot ascidian or Mytilid ascidian, has an elongated, leathery body typically reaching up to 10 cm (4 in). Its common name reflects the body's resemblance to a sheep's foot. The tough outer tunic is creamy white or yellowish, often incorporating embedded sand grains or small particles, which aids in camouflage. Two siphons are present: an incurrent siphon for drawing in water and an excurrent siphon for expelling filtered water. The edges of these siphons are frequently ringed with orange, brown, or purple. The body's surface texture ranges from smooth to slightly wrinkled.
This tunicate is common throughout the 🌊 Red Sea, attaching to hard substrates such as coral reefs, rock surfaces, and under overhangs. It occurs in shallow to moderate depths, with observations also recorded in deeper waters. As a filter feeder, P. mytiligera consumes plankton and organic particles suspended in the water column. Water is drawn in through the incurrent siphon, passed over a mucous net produced by the endostyle to trap food particles, and then expelled through the excurrent siphon.
Polycarpa mytiligera is a hermaphrodite, capable of producing both sperm and eggs. Reproduction occurs via broadcast spawning, where gametes are released into the water column for external fertilization. The resulting larvae are free-swimming and undergo a brief planktonic stage before settling onto a suitable substrate and metamorphosing into the adult form.
- elongated leathery body, wrinkled like a hoof
- reddish brown to grey, often overgrown with algae
- two siphons set close together at the top
- height up to 10 cm
